The coxsackievirus and adenovirus receptor: virological and biological beauty

Virus-Host Protein Interaction Network of the Hepatitis E Virus ORF2-4 by Mammalian Two-Hybrid Assays

Throughout their life cycle, viruses interact with cellular host factors, thereby influencing propagation, host range, cell tropism and pathogenesis. The hepatitis E virus (HEV) is an underestimated RNA virus in which knowledge of the virus-host interaction network to date is limited. Here, two related high-throughput mammalian two-hybrid approaches (MAPPIT and KISS) were used to screen for HEV-interacting host proteins. Promising hits were examined on protein function, involved pathway(s), and their relation to other viruses. We identified 37 ORF2 hits, 187 for ORF3 and 91 for ORF4. Several hits had functions in the life cycle of distinct viruses. We focused on SHARPIN and RNF5 as candidate hits for ORF3, as they are involved in the RLR-MAVS pathway and interferon (IFN) induction during viral infections. Knocking out (KO) SHARPIN and RNF5 resulted in a different IFN response upon ORF3 transfection, compared to wild-type cells. Moreover, infection was increased in SHARPIN KO cells and decreased in RNF5 KO cells. In conclusion, MAPPIT and KISS are valuable tools to study virus-host interactions, providing insights into the poorly understood HEV life cycle. We further provide evidence for two identified hits as new host factors in the HEV life cycle.

CXADR polymorphism rs6517774 modifies islet autoimmunity characteristics and exhibits sex disparity

Enteroviral infections have been linked to the development of islet autoimmunity (IA) and type 1 diabetes (T1D), and the coxsackie and adenovirus receptor (CXADR) is one of the ligands used by adenoviruses and enteroviruses for cell internalization. Two CXADR single nucleotide polymorphisms (SNPs), rs6517774 and rs2824404, were previously associated with an increased susceptibility to IA in the international TEDDY study (The Environmental Determinants of Diabetes in the Young). This study aimed to replicate the results by genotyping 2886 children enrolled in the Finnish Diabetes Prediction and Prevention study (DIPP). In our preliminary analysis of the SNPs' allelic distributions, we could not find any association with IA susceptibility. However, a stratified analysis revealed a sex disparity, since the allelic distribution of rs6517774 was different when comparing autoantibody positive females with males; a difference not seen in healthy subjects. By using HLA risk groups and sex as covariates, a Cox regression survival analysis found that the rs6517774 (A/G) SNP was associated with a lower age at seroconversion in females (Female*rs6517774-AA; HR = 1.53, p = 0.002), while introducing a protective effect in males. Accordingly, we propose that rs6517774 alters IA characteristics by modifying the age at seroconversion in a sex-dependent manner. In light of this observation, rs6517774 now joins a limited set on SNPs found to introduce sex-dependent risk effects on the age at IA initiation.

Experimental infection of foot and mouth disease virus (FMDV) upregulates the expression of Coxsackie and adenovirus receptor (CAR) in the myocardium of suckling mice

The relative overexpression of Coxsackie and adenoviral receptor (CAR) predisposes children to viral myocarditis. As the foot and mouth disease virus (FMDV) causes fatal myocarditis in calves, lambs, and piglets and belongs to the same family as the Coxsackie virus, we investigated the role of CAR in FMDV induced myocarditis in the suckling mice model. Swiss albino suckling mice of 5 days (n = 24) were divided into two equal groups. One group was inoculated with suckling mice adapted FMDV serotype O at 10 LD50, while the other group served as uninfected control. In addition, adult mice (n = 12) served as the control for age related CAR expression and lack of pathogenicity to FMDV. The establishment of myocarditis was confirmed by histopathological changes typical of myocarditis along with immunolocalization of FMDV antigens in the heart of suckling mice. The FMDV inoculated suckling mice group showed a significant upregulation of CAR transcripts by 2.5 folds, overexpression of CAR protein by densitometric analysis of immunoblots, and intense immunolocalization of CAR in the sarcolemma and intercalated discs of cardiomyocytes as compared to the uninfected suckling mice group and adult mice. It was concluded that FMDV infection induced overexpression of CAR in the myocardium of suckling mice.

Cell membrane nanomaterials composed of phospholipids and glycoproteins for drug delivery in inflammatory bowel disease: A review

Inflammatory bowel disease (IBD) is a serious chronic intestinal disorder with an increasing global incidence. However, current treatment strategies, such as anti-inflammatory drugs and probiotics, have limitations in terms of safety, stability, and effectiveness. The emergence of targeted nanoparticles has revolutionized IBD treatment by enhancing the biological properties of drugs and promoting efficiency and safety. Unlike synthetic nanoparticles, cell membrane nanomaterials (CMNs) consist primarily of biological macromolecules, including phospholipids, proteins, and sugars. CMNs include red blood cell membranes, macrophage membranes, and leukocyte membranes, which possess abundant glycoprotein receptors and ligands on their surfaces, allowing for the formation of cell-to-cell connections with other biological macromolecules. Consequently, they exhibit superior cell affinity, evade immune responses, and target inflammation effectively, making them ideal material for targeted delivery of IBD therapies. This review explores various CMNs delivery systems for IBD treatment. However, due to the complexity and harsh nature of the intestinal microenvironment, the lack of flexibility or loss of selectivity poses challenges in designing single CMNs delivery strategies. Therefore, we propose a hierarchically programmed delivery modality that combines CMNs with pH, charge, ROS and ligand-modified responsive nanoparticles. This approach significantly improves delivery efficiency and points the way for future research in this area.

Investigating the mechanism of Echovirus 30 cell invasion

Viruses invade susceptible cells through a complex mechanism before injecting their genetic material into them. This causes direct damage to the host cell, as well as resulting in disease in the corresponding system. Echovirus type 30 (E30) is a member of the Enterovirus B group and has recently been reported to cause central nervous system (CNS) disorders, leading to viral encephalitis and viral meningitis in children. In this review, we aim to help in improving the understanding of the mechanisms of CNS diseases caused by E30 for the subsequent development of relevant drugs and vaccines.

The Pathogenesis of Cytomegalovirus and Other Viruses Associated with Hearing Loss: Recent Updates

Virus infection is one of the most common etiologies of hearing loss. Hearing loss associated with viral infection can be unilateral or bilateral, mild or severe, sudden or progressive, and permanent or recoverable. Many viruses cause hearing loss in adults and children; however, the pathogenesis of hearing loss caused by viral infection is not fully understood. This review describes cytomegalovirus, the most common virus causing hearing loss, and other reported hearing loss-related viruses. We hope to provide a detailed description of pathogenic characteristics and research progress on pathology, hearing phenotypes, possible associated mechanisms, treatment, and prevention measures. This review aims to provide diagnostic and treatment assistance to clinical workers.

Resistance towards ChadOx1 nCoV-19 in an 83 Years Old Woman Experiencing Vaccine Induced Thrombosis with Thrombocytopenia Syndrome

BACKGROUND

in this report, we describe the case of an 83-year-old woman vaccinated with ChadOx1 nCoV-19 who developed a so-called vaccine-induced thrombosis with thrombocytopenia syndrome and who did not develop any antibodies against the spike protein of SARS-CoV-2 at 30 days following the administration of her first dose of ChadOx1 nCoV-19. Experimental section: two serum samples from the patient and 5 serum samples from 5 control individuals having received the two-dose regimen vaccination with ChadOx1 nCoV-19 were evaluated. In order to investigate the lack of response to the vaccination, a cell model was developed. This model permits to evaluate the interaction between responsive cells (A549) possessing the Coxsackievirus and Adenovirus Receptor (CAR), a defined concentration of ChadOx1 nCoV-19 and serial dilution of the patient or the control serum. The aim was to assess the impact of these sera on the production of the spike (S) protein induced by the transfection of the genetic material of ChadOx1 nCoV-19 into the A549 cells. The S protein is measured in the supernatant using an ELISA technique.

RESULTS

interestingly, the serum from the patient who developed the vaccine-induced thrombosis with thrombocytopenia syndrome impaired the production of S protein by the A549 cells transfected with ChadOx1 nCoV-19. This was not observed with the controls who did not interfere with the transfection of ChadOx1 nCoV-19 into A549 cells since the S protein is retrieved in the supernatant fraction.

CONCLUSION

based on the data coming from the clinical and the cell model information, we found a possible explanation on the absence of antibody response in our patient. She has, or has developed, characteristics that prevent the production of the S protein in contrast to control subjects. We were not able to investigate the entire mechanism behind this resistance which deserve further investigations. A link between this resistance and the development of the thrombosis with thrombocytopenia syndrome following vaccination with ChadOx1 nCoV-19 cannot be excluded.

Gene therapy for cystic fibrosis: Challenges and prospects

Cystic fibrosis (CF) is a life-threatening autosomal-recessive disease caused by mutations in a single gene encoding cystic fibrosis transmembrane conductance regulator (CFTR). CF effects multiple organs, and lung disease is the primary cause of mortality. The median age at death from CF is in the early forties. CF was one of the first diseases to be considered for gene therapy, and efforts focused on treating CF lung disease began shortly after the CFTR gene was identified in 1989. However, despite the quickly established proof-of-concept for CFTR gene transfer in vitro and in clinical trials in 1990s, to date, 36 CF gene therapy clinical trials involving ∼600 patients with CF have yet to achieve their desired outcomes. The long journey to pursue gene therapy as a cure for CF encountered more difficulties than originally anticipated, but immense progress has been made in the past decade in the developments of next generation airway transduction viral vectors and CF animal models that reproduced human CF disease phenotypes. In this review, we look back at the history for the lessons learned from previous clinical trials and summarize the recent advances in the research for CF gene therapy, including the emerging CRISPR-based gene editing strategies. We also discuss the airway transduction vectors, large animal CF models, the complexity of CF pathogenesis and heterogeneity of CFTR expression in airway epithelium, which are the major challenges to the implementation of a successful CF gene therapy, and highlight the future opportunities and prospects.

Adenovirus entry: Stability, uncoating, and nuclear import

Adenoviruses (AdVs) are widespread in vertebrates. They infect the respiratory and gastrointestinal tracts, the eyes, heart, liver, and kidney, and are lethal to immunosuppressed people. Mastadenoviruses infecting mammals comprise several hundred different types, and many specifically infect humans. Human adenoviruses are the most widely used vectors in clinical applications, including cancer treatment and COVID-19 vaccination. AdV vectors are physically and genetically stable and generally safe in humans. The particles have an icosahedral coat and a nucleoprotein core with a DNA genome. We describe the concept of AdV cell entry and highlight recent advances in cytoplasmic transport, uncoating, and nuclear import of the viral DNA. We highlight a recently discovered "linchpin" function of the virion protein V ensuring cytoplasmic particle stability, which is relaxed at the nuclear pore complex by cues from the E3 ubiquitin ligase Mind bomb 1 (MIB1) and the proteasome triggering disruption. Capsid disruption by kinesin motor proteins and microtubules exposes the linchpin and renders protein V a target for MIB1 ubiquitination, which dissociates V from viral DNA and enhances DNA nuclear import. These advances uncover mechanisms controlling capsid stability and premature uncoating and provide insight into nuclear transport of nucleic acids.

Protection is not always a good thing: The immune system's impact on gene therapy

There are many clinical trials underway for the development of gene therapies, and some have resulted in gene therapy products being commercially approved already. Significant progress was made to develop safer and more effective strategies to deliver and regulate genetic products. An unsolved aspect is the immune system, which can affect the efficiency of gene therapy in different ways. Here we present an overview of approved gene therapy products and the immune response elicited by gene delivery systems. These include responses against the vector or its content after delivery and against the product of the corrected gene. Strategies to overcome the hurdles include hiding the vector or/and the transgene product from the immune system and hiding the immune system from the vector/transgene product. Combining different strategies, such as patient screening and intelligent vector design, gene therapy is set to make a difference in the life of patients with severe genetic diseases.

Emerging Viral Infections and the Potential Impact on Hypertension, Cardiovascular Disease, and Kidney Disease

Viruses are ubiquitous in the environment and continue to have a profound impact on human health and disease. The COVID-19 pandemic has highlighted this with impressive morbidity and mortality affecting the world's population. Importantly, the link between viruses and hypertension, cardiovascular disease, and kidney disease has resulted in a renewed focus and attention on this potential relationship. The virus responsible for COVID-19, SARS-CoV-2, has a direct link to one of the major enzymatic regulatory systems connected to blood pressure control and hypertension pathogenesis, the renin-angiotensin system. This is because the entry point for SARS-CoV-2 is the ACE2 (angiotensin-converting enzyme 2) protein. ACE2 is one of the main enzymes responsible for dampening the primary effector peptide Ang II (angiotensin II), metabolizing it to Ang-(1-7). A myriad of clinical questions has since emerged and are covered in this review. Several other viruses have been linked to hypertension, cardiovascular disease, and kidney health. Importantly, patients with high-risk apolipoprotein L1 (APOL1) alleles are at risk for developing the kidney lesion of collapsing glomerulopathy after viral infection. This review will highlight several emerging viruses and their potential unique tropisms for the kidney and cardiovascular system. We focus on SARS-CoV-2 as this body of literature in regards to cardiovascular disease has advanced significantly since the COVID-19 pandemic.

Ligand-of-Numb protein X1 controls the coxsackievirus B3-induced myocarditis via regulating the stability of coxsackievirus and adenovirus receptor

Group B coxsackieviruses (CVBs) are the main cause of virus-induced myocarditis. CVBs use coxsackievirus and adenovirus receptor (CAR) for infection and targeting CAR has been shown to ameliorate CVBs-induced myocarditis. Ligand-of-Numb protein X1 (LNX1) is an E3 ubiquitin ligase that was shown to interact with CAR. However, the precise effect of LNX1 on CAR and the roles of LNX1 on CVBs-induced myocarditis remain unknown. In the present study, we generated mice deficient in LNX1 in the heart and evaluated the symptoms of myocarditis after CVB3 infection. We also monitored the expression and ubiquitination of CAR in LNX1-deficient cardiomyocytes after CVBs infection. We found that CVBs infection decreased CAR expression while promoted the expression of LNX1. Mice with deficiency of LNX1 in the heart had normal myocardial development while had deteriorated myocarditis symptoms after CVB3 infection. In LNX1-deficient cardiomyocytes, decreased ubiquitination of CAR and upregulation of CAR were observed after CVB3 infection. In summary, LNX1 controls CVB3-induced myocarditis by regulating the expression of CAR.

The Coxsackievirus and Adenovirus Receptor Has a Short Half-Life in Epithelial Cells

The coxsackievirus and adenovirus receptor (CAR) is an essential cellular protein that is involved in cell adhesion, cell signaling, and viral infection. The 8-exon encoded isoform (CAREx8) resides at the apical surface of polarized epithelia, where it is accessible as a receptor for adenovirus entering the airway lumen. Given its pivotal role in viral infection, it is a target for antiviral strategies. To understand the regulation of CAREx8 and determine the feasibility of receptor downregulation, the half-life of total and apical localized CAREx8 was determined and correlated with adenovirus transduction. Total and apical CAREx8 has a relatively short half-life of approximately 2 h. The half-life of apical CAREx8 correlates well with adenovirus transduction. These results suggest that antiviral strategies that aim to degrade the primary receptor for apical adenovirus infection will be effective within a relatively short time frame after application.

Possible Association of Pulmonary Atresia with In-Utero Coxsackievirus B Exposure

Gestational viral infection has been associated with congenital heart disease (CHD). Few studies, however, have studied the potential role of gestational Coxsackievirus B (CVB) exposure in the pathogenesis of CHD. We prospectively enrolled women with pregnancies affected by CHD to explore possible associations with in utero CVB exposure. Serum samples were obtained from 122 women referred for fetal echocardiography between 2006 and 2018. We quantified CVB IgG and IgM levels, with titers ≥ 15.0 U/mL considered positive and measured neutralizing antibodies for three CVB serotypes: CVB1, CVB3, and CVB4. Using data from the national enterovirus surveillance system, we compared the annual exposure rates for each serotype in our cohort to infections reported across the United States. 98 pregnancies with no genetic defects were included. Overall, 29.6% (29/98) had positive IgG and 4.1% (4/98) of women had positive CVB IgM titers. To explore first-trimester CVB exposure, we focused exclusively on the 26 women with positive IgG and negative IgM titers. 61.5% (16/26) had neutralizing antibodies against a single serotype and 38.5% (10/26) against multiple CVB serotypes. CVB4 neutralizing antibodies were the most common (65.4%, 17/26), followed by CVB3 (53.9%, 14/26) and CVB1 (30.8%, 8/26). Among these, 30.8% of babies presented pulmonary valve anomalies: 19.2% (5/26) pulmonary atresia, and 11.5% (3/26) pulmonary stenosis. 23.1% (6/26) of babies had coronary sinusoids. CVB exposure in our cohort mirrored that of reported infections in the United States. Our results suggest a possible association between gestational CVB exposure and specific CHD, particularly pulmonary valve anomalies and coronary sinusoids.

An Inter-Supplementary Biohybrid System Based on Natural Killer Cells for the Combinational Immunotherapy and Virotherapy of Cancer

Oncolytic adenoviruses (Ads) have gained great attention in cancer therapy because they cause direct cytolytic infection and indirectly induce antitumor immunity. However, their efficacy is compromised by host antiviral immune response, poor tumor delivery, and the immunosuppressive tumor microenvironment (TME). Here, a natural killer (NK) cell-mediated Ad delivery system (Ad@NK) is generated by harnessing the merits of the two components for combinational immunotherapy and virotherapy of cancer. In this biohybrid system, NK cells with a tumor-homing tropism act as bioreactors and shelters for the loading, protection, replication, amplification, and release of Ads, thereby leading to a highly efficient systemic tumor-targeted delivery. As feedback, Ad infection offers NK cells an enhanced antitumor immunity by activating type I interferon signaling in a STAT4-granzyme B-dependent manner. Moreover, it is found that the Ad@NK system can relieve immunosuppression in the TME by promoting the maturation of dendritic cells and the polarization of macrophages to M1 phenotype. Both in vitro and in vivo data indicate the excellent antitumor and antimetastatic functions of Ad@NKs by destroying tumor cells, inducing immunogenic cell death, and immunomodulating TME. This work provides a clinical basis for improved oncolytic virotherapy in combination with NK cell therapy based on the inter-supplementary biohybrid system.

Adenovirus Type 6: Subtle Structural Distinctions from Adenovirus Type 5 Result in Essential Differences in Properties and Perspectives for Gene Therapy

Adenovirus vectors are the most frequently used agents for gene therapy, including oncolytic therapy and vaccine development. It’s hard to overestimate the value of adenoviruses during the COVID-19 pandemic as to date four out of four approved viral vector-based SARS-CoV-2 vaccines are developed on adenovirus platform. The vast majority of adenoviral vectors are based on the most studied human adenovirus type 5 (HAdV-C5), however, its immunogenicity often hampers the clinical translation of HAdV-C5 vectors. The search of less seroprevalent adenovirus types led to another species C adenovirus, Adenovirus type 6 (HAdV-C6). HAdV-C6 possesses high oncolytic efficacy against multiple cancer types and remarkable ability to induce the immune response towards carrying antigens. Being genetically very close to HAdV-C5, HAdV-C6 differs from HAdV-C5 in structure of the most abundant capsid protein, hexon. This leads to the ability of HAdV-C6 to evade the uptake by Kupffer cells as well as to distinct opsonization by immunoglobulins and other blood proteins, influencing the overall biodistribution of HAdV-C6 after systemic administration. This review describes the structural features of HAdV-C6, its interaction with liver cells and blood factors, summarizes the previous experiences using HAdV-C6, and provides the rationale behind the use of HAdV-C6 for vaccine and anticancer drugs developments.

Coxsackievirus and Adenovirus Receptor (CXADR): Recent Findings and Its Role and Regulation in Spermatogenesis

Coxsackievirus and adenovirus receptor (CXADR) belongs to immunoglobulin superfamily of cell adhesion molecules. It expresses in most tissues, but displays unique and indispensable functions in some tissues such as heart and testis. CXADR is a multifunctional protein that can serve as a viral receptor, a junction structural protein and a signalling molecule. Thus, it exerts a wide range of functions such as facilitating leukocyte transmigration, regulating barrier function and cell adhesion, promoting EMT transition, and mediating spermatogenesis. This review aims to provide an overview and highlights some recent findings on CXADR in the field with emphasis on studies in the testis, upon which future studies can be designed to delineate the roles and regulation of CXADR in spermatogenesis.

Antigen Presentation of mRNA-Based and Virus-Vectored SARS-CoV-2 Vaccines

Infection with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) causes Coronavirus Disease 2019 (COVID-19), which has reached pandemic proportions. A number of effective vaccines have been produced, including mRNA vaccines and viral vector vaccines, which are now being implemented on a large scale in order to control the pandemic. The mRNA vaccines are composed of viral Spike S1 protein encoding mRNA incorporated in a lipid nanoparticle and stabilized by polyethylene glycol (PEG). The mRNA vaccines are novel in many respects, including cellular uptake and the intracellular routing, processing, and secretion of the viral protein. Viral vector vaccines have incorporated DNA sequences, encoding the SARS-CoV-2 Spike protein into (attenuated) adenoviruses. The antigen presentation routes in MHC class I and class II, in relation to the induction of virus-neutralizing antibodies and cytotoxic T-lymphocytes, will be reviewed. In rare cases, mRNA vaccines induce unwanted immune mediated side effects. The mRNA-based vaccines may lead to an anaphylactic reaction. This reaction may be triggered by PEG. The intracellular routing of PEG and potential presentation in the context of CD1 will be discussed. Adenovirus vector-based vaccines have been associated with thrombocytopenic thrombosis events. The anti-platelet factor 4 antibodies found in these patients could be generated due to conformational changes of relevant epitopes presented to the immune system.

Cryo-EM structures reveal the molecular basis of receptor-initiated coxsackievirus uncoating

Enterovirus uncoating receptors bind at the surface depression ("canyon") that encircles each capsid vertex causing the release of a host-derived lipid called "pocket factor" that is buried in a hydrophobic pocket formed by the major viral capsid protein, VP1. Coxsackievirus and adenovirus receptor (CAR) is a universal uncoating receptor of group B coxsackieviruses (CVB). Here, we present five high-resolution cryoEM structures of CVB representing different stages of virus infection. Structural comparisons show that the CAR penetrates deeper into the canyon than other uncoating receptors, leading to a cascade of events: collapse of the VP1 hydrophobic pocket, high-efficiency release of the pocket factor and viral uncoating and genome release under neutral pH, as compared with low pH. Furthermore, we identified a potent therapeutic antibody that can neutralize viral infection by interfering with virion-CAR interactions, destabilizing the capsid and inducing virion disruption. Together, these results define the structural basis of CVB cell entry and antibody neutralization.

Adenoviruses - Infection, pathogenesis and therapy

Both well-known and emerging viruses increasingly affect humans and cause disease, sometimes with devastating impact on society. The viruses present in the biosphere are the top predators in the life chain, virtually without enemies, except perhaps the immune system, and harsh environmental physicochemical conditions restricting their dissemination. We know a lot about viruses, but do we know enough? This series of reviews is dedicated to adenoviruses (AdVs), a family of nonenveloped DNA viruses occurring in vertebrates, including humans. AdVs have been the focus of intense research for more than 67 years. Besides causing disease, they have immensely contributed to the advance of life sciences and medicine over the past decades. Recently, AdVs have been widely used as vehicles in gene therapy and vaccination. They continue to provide fundamental insights into virus-host interactions in cells, tissues and organisms, as well as systems and metabolic networks. This special issue of FEBS Letters presents a unique collection of 23 state-of-the-art review articles by leading adenovirologists. In this prelude, I present the chapters, which provide a solid basis for further exploring the rich heritage in adenovirus molecular cell biology, structural biology, genetics, immunology, gene therapy and epidemiology. I conclude with an essential discussion of six blind spots in adenovirology.